Operating tables, trolleys and transfer systems

Abstract: A transfer trolley 3 for transferring a patient onto an operating table 1 has a removable patient support platform 4 divided across its length into two parts 40 and 41 coupled by a hinge 42. A rod 46 and cylinder 47 mounted at their ends to respective parts of the platform are lockable to lock the two parts of the platform and prevent bending at the hinge while on the trolley. The trolley has two arms 28, 78 for supporting the platform, which either extend laterally under the platform on opposite sides of the hinge or longitudinally and traversing the region of the hinge. A control unit 32 on the trolley 3 has infra-red emitters 33 that emit signals to sensors 51 on the table 1, to control operation of the table, only when the trolley is correctly located for transfer.

Description: This invention relates to transfer trolleys of the kind for use in transferring a patient onto an operating table, the trolley including a removable patient support platform divided across its length into two parts coupled at a hinge, the platform being lockable to prevent bending at the hinge while on the trolley. Such a trolley is known from FR-A-1.322.712. Instead of lifting a patient off a trolley and onto an operating table, it is common practice for the top, or patient support platform, of the trolley to be removable so that this can be transferred onto the operating table support column. The platform is then used to support the patient during surgery and is articulated and displaceable by means of the operating table controls. After surgery, the patient support platform is moved back onto the trolley so that the patient can be transferred to the recovery room. This arrangement minimizes disturbance of the patient and reduces the amount of lifting that needs to be done by theatre staff. The patient support platform is usually supported by the trolley and the operating table at the hinge point of the platform, that is, the point at which the two ends of the platform form an acute or obtuse angle when the ends are raised or lowered relative to one another. One problem with this arrangement is that different platforms are needed for side loading and for end loading. Another problem with these transfer systems is in controlling the loading and unloading operations. It is possible in some systems for the user to start loading or unloading of the table before the trolley is in the correct position. This can lead to damage or injury. It is an object of the present invention in its various objects to provide an improved operating table, trolley and transfer system. According to the present invention there is provided a transfer trolley of the above-specified kind, characterised in that the trolley includes supports for supporting the platform at locations spaced along the platform on opposite sides of the hinge, characterised in that the trolley includes a control unit supplying signals to an operating table to control operation of the operating table. The control unit is preferably arranged so that signals are only received by the operating table when the trolley is in the correct position to transfer the patient support platform to or from the operating table. The control unit may include an infrared emitter arranged to supply signals to an infrared sensor on the operating table. The platform may include a rod and cylinder mounted at their ends to respective parts of the platform, the rod being slidable in the cylinder and being lockable relative to the cylinder. A trolley, operating table and transfer system, in accordance with the present invention will now be described, by way of example, with reference to the accompanying drawings in which: Figure 1 is a perspective view of the system; Figure 2 is a perspective view of the trolley; Figure 3 is a side elevation view of a patient support platform; and Figure 4 is a side elevation view of the operating table. With reference first to Figure 1 there is shown an operating table 1 used with a side-loading trolley 2 and an end-loading trolley 3. The side-loading trolley 2 is illustrated in position (A) carrying the patient support platform 4. The patient is placed on the platform 4 and is moved to the operating theatre by means of the trolley 2. The trolley 2 is moved in position over the operating table, which is then raised to lift the platform off the trolley. Locks on the operating table engage the platform 4 to retain it in position. The trolley 2 is then moved back to position (B) where it is shown without the platform 4. The end-loading trolley 3 is used similarly. With reference now to Figure 2, the trolley 2 has a U-shape metal base 20 formed by two parallel feet 21 joined at one end by a cross-piece 22. The base 20 has four wheels or castors 23, one at each corner. A fifth castor 23' is located midway along the cross-piece 22, this castor being lockable in orientation in order to help guide the trolley in straight lines when it is being pushed. The internal length of the base 20, between the feet 21 is selected to be slightly greater than the length of the base 10 of the operating table. A vertical pillar 24 projects from the centre of the cross-piece 22 to a height just exceeding the lowest height setting of the operating table column 11. At the upper end of the pillar 24 there is a platform support frame 25, which is of U-shape and extends horizontally from the pillar over the base 20. The frame 25 has a cross-piece 26 that extends parallel with the cross-piece 22 of the base and projects an equal distance on opposite sides of the pillar 24. Centrally of the cross-piece 26 there is a wedge-shape member 27 that projects vertically upwards. The frame 25 also has two arms 28 extending parallel to one another at right angles to and at opposite ends of the cross-piece 26. Both arms have two sockets 29 at their ends that receive locking pins from the platform 4. The trolley 2 also has two L-shape manoeuvring bars 30 and 31, which extend longitudinally and down from the upper, platform support frame 25 at opposite ends of the trolley. These are used to push and pull the trolley and do not support the platform 4. The trolley 2 also includes a hand-held control unit 32 used to control up and down operation of the table 1. The control unit 32 is battery powered and provides an output to two short-range infra-red emitters 33 located on the inside of the feet 21 midway along their length. Operation of the control unit 32 will be described later. With reference now to Figure 3, the patient support 4 has two leaves 40 and 41 linked together by a lateral hinge 42 so that the two leaves can each be displaced up or down about the hinge axis. At opposite ends of the hinge 42 there are two support plates 43 having wedge-shape recesses 44 on their outer surfaces; these recesses are of the same shape as the members 27. On their inner surfaces, the plates 43 both have locking recesses that receive a laterally-expandable bolt (not shown) from the table 1, which serves to lock the platform on the table. The platform 4 also has a locking mechanism 45 connected between the two leaves 40 and 41 so that they can be locked relative to one another to prevent bending at the hinge 42 The locking mechanism 45 may take various different forms. In the example illustrated, it comprises a rod 46 and a cylinder 47 pivotally mounted at their ends with respective leaves 40 and 41. The rod 46 is slidable inside the cylinder and can be locked relative to the cylinder by means of a lock 48. Alternative locking mechanisms include an hydraulic or pneumatic damper cylinder that prevents relative movement when a vent in the cylinder is closed but allows relative movement when the vent is open. In normal use of the operating table 1, the locking mechanism 45 is unlocked so that the two leaves 40 and 41 can be moved freely relative to one another. When the platform 4 is on the trolley 2, the locking mechanism 45 is locked. This is necessary to ensure that the platform does not fold at the hinge 42 during transfer since the two arms 28 of the trolley extend laterally under the platform on opposite sides of the hinge. With the end-loading trolley 3 the two arms 78 extend longitudinally under the platform and traverse the region of the hinge 42. The operating table 1 has a rectangular base 10 that sits on the floor. At opposite ends of the base 10 there are two infra-red sensors 51 positioned to be alongside the emitters 33 on the trolley 2 when the trolley is in the correct position relative to the table. A column 52 extends upwardly from the base 10 and has at its upper end an articulated platform retainer 53 by which the various movements of the parts of the platform are effected. The retainer 53 has a lock 54 that locks the platform 4 to the table 1. The column 52 contains various hydraulic actuators 55 linked to the retainer 53. The table 1 has a conventional handset 56 used to move the platform up and down and to cause the usual tilting movements of the platform 4 and its two leaves 40 and 41. The handset 56 is connected via a cable 57 to a control unit 58 in the base 10, which also contains an hydraulic power supply 59 for the table. The handset 56 can be held in the hand by the surgeon or other theatre staff when movement of the table is required. At other times, the handset 56 sits in a receptacle 60 on the table. The receptacle 60 includes a sensor 61 responsive to the handset 56; the sensor provides a signal to the control unit 58 to indicate whether or not the handset is in the receptacle. To load a patient onto the operating table 1, the table column 52 is first lowered to its full extend by using the table handset 56. The handset 56 is then placed in the receptacle 60. The trolley 2, with the platform 4 supporting the patient, is then pushed up to the operating table 1 so that its feet 21 extend either side of the base 10 and so that the cross-piece 22 abuts the longitudinal side of the base. In this position, the platform 4 is located correctly above the table 1 and its platform retainer 53 and the emitters 33 are located in register with the sensors 51 on the base. The next step is to raise the column 52 of the table 1 so that the platform 4 is lifted off the trolley 2 and is locked onto the retainer 53 of the table. This is carried out by means of the trolley's control unit 32. Actuation of the UP key on the control unit 32 causes coded emissions of infra-red pulses from the emitters 53, which are received by the sensors 51. The sensors 51 supply signals to the control unit 58 in the base 10 causing the control unit to raise the column 52. This only happens if the control unit 58 in the base 1 receives a signal from the receptacle sensor 61 to indicate that the table handset 56 is correctly stowed. This feature ensures that the table 1 is only controlled by one person during transfer and ensures that the cable 57 of the table handset 56 is not trapped during transfer. Because the control unit 32 can only control the table 1 when the trolley 2 is correctly positioned, it reduces the risk of the platform being incorrectly loaded onto the table or onto the trolley. When the weight of the platform 4 is taken by the table retainer 53, the platform is automatically locked to the retainer by the expanding bolt in the lock 54. The trolley 2 is then removed and the table is controlled in the usual way using its handset 56. The control unit 32 on the trolley 2 becomes ineffective as soon as the trolley is moved away from the table because the sensors 51 in the base 10 no longer respond to the emitters 33. When surgery has been completed, the table 1 is raised so that the trolley 2 can be moved under the platform 4. Again, the handset 56 of the table is placed in the receptacle 60 before the trolley is moved into position. Lowering of the table is controlled by the control unit 32 on the trolley 2. The platform 4 can also be transferred using the end-loading trolley 3. This is similar in construction to the side-loading trolley 2 except that it has two pillars 74 and 74' supporting the patient support frame 75. The separation between the feet 71 of the trolley 3 is less than with the other trolley 2 and just greater than the width of the base 10 of the table 1. The trolley 3 has one emitter 73 located centrally of the cross-piece 72 between the two feet. In use, the platform 4 is supported by means of wedge-shape members 79 on the arms 78, which locate in the wedge-shape recesses 44 on the platform.

Claims: A transfer trolley for use in transferring a patient onto an operating table, the trolley including a removable patient support platform divided across its length into two parts coupled at a hinge, the platform being lockable to prevent bending at the hinge while on the trolley, characterised in that the trolley (3) includes supports (28, 78) for supporting the platform at locations spaced along the platform on opposite sides of the hinge, and in that the trolley (3) includes a control unit (32) supplying signals to an operating table (1) to control operation of the operating table. A trolley according to Claim 1, characterised in that the control unit (32) is arranged so that signals are only received by the operating table (1) when the trolley is in the correct position to transfer the patient support platform (4) to or from the operating table. A trolley according to Claim 1 or 2, characterised in that the control unit (32) includes an infrared emitter (33) arranged to supply signals to an infra-red sensor (51) on the operating table (1). A trolley according to any one of the preceding claims, characterised in that the platform includes a rod (46) and cylinder (47) mounted at their ends to respective parts (40, 41) of the platform, and that the rod is slidable in the cylinder and is lockable relative to the cylinder.

Inventors: HANNANT KEITH, STACHAN JULIE, HANNANT, KEITH, STACHAN, JULIE
Applicants: SMITHS INDUSTRIES PLC, SMITHS INDUSTRIES PUBLIC LIMITED COMPANY
Application year: 1994
Main classification: A61G7
IPC codes: A61G7, A61G13, A61G3